MR imaging of the gallbladder

Ultrasound of the gallbladder: not the same bag of tricks

Imaging evaluation of the gallbladder is a fundamental skill in the majority of radiology practice. Due to ease of accessibility, low cost, lack of ionizing radiation, and excellent spatial resolution, ultrasound is often the first imaging modality used to evaluate the gallbladder. In this invited article we review and update how ultrasound can evaluate common pathologies including gallbladder polyps, tumefactive sludge, adenomyomatosis, and acute cholecystitis. We also discuss the role of Doppler, microvascular flow imaging, and contrast enhanced ultrasound in the sonographic assessment of the gallbladder.

Congenital absence of the gallbladder in a child: a case report

Background

Congenital absence of the gallbladder (CAGB) is an exceedingly rare embryological anomaly of the biliary system, with a complex etiology involving the failure of gallbladder formation during embryogenesis. Clinical manifestations are diverse; most patients are asymptomatic, while some present with symptoms such as biliary colic. The complexity of its clinical presentation and radiological features renders diagnosis challenging.

Case presentation

Fetal ultrasound at 22 weeks of gestation revealed an absent gallbladder. At 9 years and 11 months of age, the child exhibited significant weight gain and abnormalities. Abdominal ultrasound and magnetic resonance images demonstrated fatty liver and gallbladder agenesis. Liver function tests indicated mild abnormalities, with aspartate aminotransferase at 67 IU/L and alanine aminotransferase at 44 IU/L. Following 6 months of hepatoprotective and lipid-lowering therapy, a satisfactory treatment response was achieved, with normalization of liver function and improvement in fatty liver.

Conclusions

CAGB may be associated with other congenital abnormalities, although isolated cases are uncommon. Clinically, it may manifest as nonspecific biliary, gastrointestinal, or urinary symptoms, mimicking various digestive disorders and leading to misdiagnosis. Genetic sequencing and in-depth embryological research may elucidate the etiology and enhance diagnostic accuracy.

Traveling gallstones: review of MR imaging and surgical pathology features of gallstone disease and its complications in the gallbladder and beyond

Gallstone-related disease comprises a spectrum of conditions resulting from biliary stone formation, leading to obstruction and inflammatory complications. These can significantly impact patient quality of life and carry high morbidity if not accurately detected. Appropriate imaging is essential for evaluating the extent of gallstone disease and assuring appropriate clinical management. Magnetic Resonance Imaging (MRI) techniques (including Magnetic Resonance Cholangiopancreatography (MRCP) are increasingly used for diagnosis of gallstone disease and its complications and provide high contrast resolution and facilitate tissue-level assessment of gallstone disease processes. In this review we seek to delve deep into the spectrum of MR imaging in diagnose of gallstone-related disease within the gallbladder and complications related to migration of the gallstones to the gall bladder neck or cystic duct, common hepatic duct or bile duct (choledocholithiasis) and beyond, including gallstone pancreatitis, gallstone ileus, Bouveret syndrome, and dropped gallstones, by offering key examples from our practice. Furthermore, we will specifically highlight the crucial role of MRI and MRCP for enhancing diagnostic accuracy and improving patient outcomes in gallstone-related disease and showcase relevant surgical pathology specimens of various gallstone related complications.

The Use of a New Dedicated Electrocautery Lumen-Apposing Metal Stent for Gallbladder Drainage in Patients with Acute Cholecystitis

Aims: Lumen-apposing metal stents (LAMSs) in ultrasonography-guided gallbladder drainage (EUS-GBD) have become increasingly important for high-risk surgical patients. Our study aims to evaluate the technical and clinical success, safety, and feasibility of endoscopic ultrasonography-guided gallbladder drainage using a new dedicated LAMS. Methods: This is a retrospective multicenter study that included all consecutive patients not suitable for surgery who were referred to a tertiary center for EUS-GBD using a new dedicated electrocautery LAMS for acute cholecystitis at eight different centers. Results: Our study included 54 patients with a mean age of 76.48 years (standard deviation: 12.6 years). Out of the 54 endoscopic gallbladder drainages performed, 24 (44.4%) were cholecysto-gastrostomy, and 30 (55.4%) were cholecysto-duodenostomy. The technical success of LAMS placement was 100%, and clinical success was achieved in 23 out of 30 patients (76.67%). Adverse events were observed in two patients (5.6%). Patients were discharged after a median of 5 days post-stenting. Conclusions: EUS-GBD represents a valuable option for high-surgical-risk patients with acute cholecystitis. This new dedicated LAMS has demonstrated a high rate of technical and clinical success, along with a high level of safety.

The gallbladder: what's new in 2022?

This review focuses mainly on the imaging diagnosis, treatment, and complications of acute cholecystitis which is the most common benign disease of the gallbladder. The American College of Radiology appropriateness criteria for the imaging evaluation of patients with right upper quadrant pain and the Tokyo Guidelines for evaluating patients with acute cholecystitis and acute cholangitis are presented. The recent articles for using US, CT, MR, and HIDA in the evaluation of patients with suspected acute cholecystitis are reviewed in detail. The clinical management and postoperative complications are described. Because gallbladder polyps and adenomyomatosis can mimic gallbladder malignancies and acute cholecystitis, their imaging findings and management are presented. Finally, due the recent literature reporting better results with CT than US in the diagnosis of acute cholecystitis, a suggested approach for imaging patients with right upper quadrant pain and possible acute cholecystitis is presented in an addendum.

Use of MR in Pancreaticobiliary Emergencies

This article presents the MR protocols, imaging features, diagnostic criteria, and complications of commonly encountered emergencies in pancreaticobiliary imaging, which include pancreatic trauma, bile leak, acute cholecystitis, biliary obstruction, and pancreatitis. Various classifications and complications that can arise with these conditions, as well as artifacts that may mimic pathology, are also included. Finally, the emerging utility of abbreviated MR protocols is discussed.

Acute Cholecystitis: A Review

IMPORTANCE

Gallbladder disease affects approximately 20 million people in the US. Acute cholecystitis is diagnosed in approximately 200 000 people in the US each year.

OBSERVATIONS

Gallstone-associated cystic duct obstruction is responsible for 90% to 95% of the cases of acute cholecystitis. Approximately 5% to 10% of patients with acute cholecystitis have acalculous cholecystitis, defined as acute inflammation of the gallbladder without gallstones, typically in the setting of severe critical illness. The typical presentation of acute cholecystitis consists of acute right upper quadrant pain, fever, and nausea that may be associated with eating and physical examination findings of right upper quadrant tenderness. Ultrasonography of the right upper quadrant has a sensitivity of approximately 81% and a specificity of approximately 83% for the diagnosis of acute cholecystitis. When an ultrasound result does not provide a definitive diagnosis, hepatobiliary scintigraphy (a nuclear medicine study that includes the intravenous injection of a radiotracer excreted in the bile) is the gold standard diagnostic test. Following diagnosis, early (performed within 1-3 days) vs late (performed after 3 days) laparoscopic cholecystectomy is associated with improved patient outcomes, including fewer composite postoperative complications (11.8% for early vs 34.4% for late), a shorter length of hospital stay (5.4 days vs 10.0 days), and lower hospital costs. During pregnancy, early laparoscopic cholecystectomy, compared with delayed operative management, is associated with a lower risk of maternal-fetal complications (1.6% for early vs 18.4% for delayed) and is recommended during all trimesters. In people older than 65 years of age, laparoscopic cholecystectomy is associated with lower mortality at 2-year follow-up (15.2%) compared with nonoperative management (29.3%). A percutaneous cholecystostomy tube, in which a drainage catheter is placed in the gallbladder lumen under image guidance, is an effective therapy for patients with an exceptionally high perioperative risk. However, percutaneous cholecystostomy tube placement in a randomized trial was associated with higher rates of postprocedural complications (65%) compared with laparoscopic cholecystectomy (12%). For patients with acalculous acute cholecystitis, percutaneous cholecystostomy tube should be reserved for patients who are severely ill at the time of diagnosis; all others should undergo a laparoscopic cholecystectomy.

CONCLUSIONS AND RELEVANCE

Acute cholecystitis, typically due to gallstone obstruction of the cystic duct, affects approximately 200 000 people in the US annually. In most patient populations, laparoscopic cholecystectomy, performed within 3 days of diagnosis, is the first-line therapy for acute cholecystitis.

Problem-solving with MRI in acute abdominopelvic conditions, part 1: gastrointestinal, hepatobiliary, and pancreatic diseases

The purpose of this article is to review the benefit and added value and advantages of magnetic resonance imaging (MRI) compared with other cross-sectional imaging in patients presenting with abdominopelvic emergencies. During the past decade, there has been increased utilization of MRI in the emergency department with widespread availability of MR scanners, improvement in rapid imaging techniques, and methods to overcome motion-related artifacts. This has benefited patients at higher risk of radiation, particularly children and pregnant women, and patients with contraindications to iodinated contrast including allergy and renal dysfunction. Still the challenges are: on site MR scanner in the emergency department, after-hour services, as well as availability of time slot to rapidly scan emergency patient. MRI has additional advantages over other imaging modalities due to its high contrast resolution, which allows it to better characterize tissue and fluid collections, and may avoid the need for intravenous contrast. Radiologists must be familiar with the role and added value of MRI, spectrum of imaging findings, and problem-oriented modified MR protocols in abdominal and pelvic emergencies. In part 1, we will discuss the utility of MRI in gastrointestinal, hepatobiliary, and pancreatic diseases. In part 2, the authors will focus on the key MR imaging features of female pelvic gynecological diseases, pregnancy related complications, abdominal vascular complications, and renal diseases.

Unenhanced MRI of the Abdomen and Pelvis in the Comprehensive Evaluation of Acute Atraumatic Abdominal Pain in Children

OBJECTIVE. The purpose of this study is to show the utility of rapid unenhanced MRI in the comprehensive assessment of acute atraumatic abdominal pain in children, including appendicitis and alternate diagnoses, and to review the MRI features of common acute abdominal and pelvic conditions in a large, single-institution cohort. CONCLUSION. Rapid unenhanced MRI is an excellent option for the initial, comprehensive evaluation of acute abdominal emergencies in pediatric patients because it can diagnose the full range of presenting abnormalities, including causes of abdominal pain warranting surgical and nonsurgical management.

Utility of MR Imaging in Abdominopelvic Emergencies

Acute abdominopelvic pain, a common symptom in emergency department patients, is challenging given the spectrum of differential diagnoses encompassing multiple organ systems, ranging from benign self-limiting to life-threatening and emergent. Diagnostic imaging is critical given its high accuracy and management guidance. A contrast-enhanced computed tomography (CT) scan is preferred given its widespread availability and speed of acquisition. MR imaging may be appropriate, usually performed for specific indications with tailored protocols. It is accurate for diagnosis and may be an alternative to CT. This article discusses the advantages and disadvantages, protocols, and appearances of MR imaging of common diagnoses.

CT diagnosis of gallbladder adenomyomatosis: importance of enhancing mucosal epithelium, the "cotton ball sign"

OBJECTIVES

To determine the diagnostic value of the cotton ball sign and other CT features in patients with gallbladder (GB) wall thickenings (WTs).

METHODS

Three blinded readers reviewed the preoperative CT and MR images of 101 patients with pathologically confirmed GB adenomyomatosis (GA) (n = 34) and other benign (n = 29), malignant (n = 41), and premalignant (n = 2) GBWTs. Three readers analysed the morphological features of GBWT and presence of the "cotton ball sign", defined as fuzzy grey dots in GBWT or a dotted outer border of the inner enhancing layer on contrast-enhanced (CE) CT. In addition, the "pearl necklace sign" on MR was analysed.

RESULTS

In the GA group (n = 34), prevalence of the cotton ball sign and pearl necklace sign was 74% (25/34) and 44% (15/34), respectively. Presence of the cotton ball sign, smooth contour of the mucosa, double-layering enhancement, and enhancement degree weaker than the renal cortex on CT images were significant predictors of benign GBWT (p < 0.01). When differentiating GA from GB malignancy or premalignancy, accuracy of the cotton ball sign and pearl necklace sign was 81% (62/77) and 74% (57/77), respectively.

CONCLUSION

The cotton ball sign on CE-CT showed higher sensitivity and comparable specificity to those of the pearl necklace sign in differentiating GA from malignancy.

KEY POINTS

• Prevalence of the cotton ball sign on CT was 74% in gallbladder adenomyomatosis. • The cotton ball sign was useful in differentiating gallbladder adenomyomatosis from gallbladder cancer. • The cotton ball sign was more sensitive than the pearl necklace sign for adenomyomatosis diagnosis.

A literature review of radiological findings to guide the diagnosis of gallbladder adenomyomatosis

BACKGROUND

Gallbladder adenomyomatosis (GA) is a benign gallbladder entity discovered as an asymptomatic gallbladder mass. Since gallbladder cancer is in the differential diagnosis for gallbladder masses, the ability to differentiate benign disease avoids a more extensive oncologic resection. This study sought to review imaging modalities used to diagnose GA.

METHODS

PubMed and SciVerse Scopus were systematically searched using the terms: "gallbladder adenomyomatosis" and "gallbladder imaging" for articles published between January 2000 and January 2015.

RESULTS

A total of 14 articles were reviewed in this analysis. Contemporary series report the use of ultrasound (US), computed tomography (CT) or magnetic resonance imaging (MRI) in GA imaging. Ultrasound detection of Rokitansky-Aschoff sinuses, visualized as small cystic spaces with associated "comet-tail" or "twinkling" artifact, is pathognomonic for GA. A "Pearl-Necklace" sign of small connected sinuses on MRI or "Rosary" sign on CT are additional characteristics that may assist in establishing a diagnosis.

CONCLUSION

Ultrasound is the most commonly used tool to investigate GA. If not diagnostic, CT or MRI are effective in attempting to differentiate a benign or malignant cholecystic mass. Characteristic signs should lead the surgeon to perform a laparoscopic cholecystectomy in symptomatic patients or manage non-operatively in asymptomatic patients.

Agenesis of the gallbladder diagnosed by magnetic resonance cholangiography: report of a case and review of the literature

Gallbladder agenesis (GA) is a rare congenital anomaly of the biliary system often associated with other congenital abnormalities. Patients become symptomatic in 23% of cases (Richards et al., 1993). GA is often misinterpreted as other diseases, therefore, leading to unnecessary surgery. Many of these patients develop a typical symptomatology of cholelithiasis that leads them to operating theatre. If an operative procedure is done, it is better to remain at the level of laparoscopy because further surgical investigation may lead to detrimental biliary tract injuries (Waisberg et al., 2002). We present a case of GA, diagnosed by magnetic resonance with cholangiopancreatography.

Nuclear medicine tests for acute gastrointestinal conditions

Acute cholecystitis (AC) and lower-gastrointestinal (GI) bleeding are 2 emergencies commonly encountered in nuclear medicine. Evidence of AC on hepatobiliary scintigraphy (HBS) allows for confident diagnosis and provides support for definitive surgical treatment. Proper patient preparation is essential for HBS including fasting and the use of pharmacologic adjuncts is sometimes required. Pharmacologic adjuncts may also be administered during HBS to shorten the length of the examination and increase its specificity. In the interpretation of HBS, there are several sources of false-positive results to be aware of, most commonly chronic cholecystitis. False-negative results on HBS are usually the result of mistaking another structure, such as a dilated cystic duct, for the gallbladder. Abdominal ultrasound is the appropriate initial test in patients with suspected AC, but HBS is an excellent second tier test for the diagnosis of AC in the work-up of indeterminate cases by sonography. GI bleeding scintigraphy plays an important role in the evaluation and management of patients with acute lower-GI bleeding. Scintigraphy serves to localize sites of active GI bleeding and stratify those patients who would benefit from aggressive treatment (surgery or arteriography) vs those who can be managed medically. Pretest involvement of respective services is critical for successful bleeding site confirmation and therapy by interventional radiology or surgery or both. Single photon emission computed tomography/computed tomography erythrocyte scintigraphy has demonstrated superior accuracy and precision over planar scintigraphy in the diagnosis of acute GI bleeding. Additionally, single photon emission computed tomography/computed tomography scintigraphy of GI bleeding provides useful supplemental anatomical information that benefits patient management.

Hepatobiliary scintigraphy in acute cholecystitis

Hepatobiliary scintigraphy is a mature imaging technique for evaluation of patients with acute cholecystitis (AC). It is effective in calculous and acalculous forms of AC. The test is used in contemporary medical practice as the arbiter when the findings from screening abdominal ultrasound do not fit a clinical picture. It is also performed in severely ill patients who have AC suspected on other testing, but whose frail condition and high operative risk demand the highest level of certainty. This review, therefore, examines all technique variations of hepatobiliary scintigraphy, offering an approach that may best fit a variety of clinical situations and philosophies on AC.

Gallbladder agenesis and cystic duct absence in an adult patient diagnosed by magnetic resonance cholangiography: report of a case and review of the literature

Gallbladder agenesis (GA) is a rare congenital anomaly of the biliary system often associated with other congenital abnormalities. Patients become symptomatic in 23% of cases. GA is often misinterpreted as other diseases, therefore, leading to unnecessary surgery. We report a case of congenital GA associated to cystic duct absence and a biliary tract abnormality diagnosed by Magnetic Resonance with Cholangiopancreatography.

Imaging of adenomyomatosis of the gall bladder

Adenomyomatosis is a relatively common abnormality of the gall bladder, with a reported incidence of between 2.8 and 5%. Although mainly confined to the adult study group, a number of cases have been reported in the paediatric study group. It is characterized pathologically by excessive proliferation of the surface epithelium and hypertrophy of the muscularis propria of the gall bladder wall, with invagination of the mucosa into the thickened muscularis forming the so-called 'Rokitansky-Aschoff' sinuses. The condition is usually asymptomatic and is often diagnosed as an incidental finding on abdominal imaging. The radiological diagnosis is largely dependent on the visualization of the characteristic Rokitansky-Aschoff sinuses. As the condition is usually asymptomatic, the importance of making a correct diagnosis is to prevent misinterpretation of other gall bladder conditions such as gall bladder cancer, leading to incorrect treatment. In the past, oral cholecystography was the main imaging method used to make this diagnosis. In most institutions, oral cholecystography is no longer carried out, and the diagnosis is now more commonly seen on cross-sectional imaging. In this review article, we describe the manifestations of adenomyomatosis on the various imaging methods, with an emphasis on more modern techniques such as magnetic resonance cholangiopancreatography. A brief section on oral cholecystography to aid readers familiar with this technique in understanding the comparable imaging features on more modern imaging techniques is included.

MR imaging of acute biliary disorders

In patients with acute right-sided epigastric pain, jaundice, and a high fever, it is essential to accurately diagnose the cause of the symptoms, differentiate acute biliary disorders from nonbiliary disorders, and evaluate the severity of the disease. Gray-scale ultrasonography (US) and computed tomography (CT) are useful primary imaging modalities, but their results are not always conclusive. Magnetic resonance (MR) imaging, including MR cholangiopancreatography, can be a valuable complement to US and CT when additional information is needed. MR images have excellent tissue contrast and can provide more specific information, allowing diagnosis of complications that arise from acute cholecystitis, such as empyema, gangrenous cholecystitis, gallbladder perforation, enterocholecystic fistula, emphysematous cholecystitis, and hemorrhagic cholecystitis. In addition, causes of obstructive jaundice, acute suppurative cholangitis, and hemobilia can be clearly demonstrated with multisequence MR imaging. Single-section MR cholangiopancreatography and heavily T2-weighted imaging, in combination with fat-suppressed T1- and T2-weighted imaging, provide comprehensive and detailed information about the biliary system around the obstruction site, biliary calculi, inflammatory processes, purulent material, abscesses, gas, and hemorrhage. Contrast-enhanced MR imaging is useful for evaluation of the gallbladder wall; lack of enhancement and disruption of the wall may be findings specific for gangrenous cholecystitis and gallbladder perforation, respectively.

MR Imaging Evaluation of Acute Abdominal Pain During Pregnancy

MR imaging enables diagnosis of a variety of maternal diseases presenting as acute abdominal pain in pregnant patients. MR imaging is a valuable complement to ultrasound in the determination of the exact etiology of acute abdominal pain, and it is important for the radiologist to recognize the MR imaging appearance of common causes of acute abdominal pain during pregnancy. This article reviews the MR imaging technique and findings of various abnormalities causing acute abdominal pain in pregnant patients.

Agenesis of the gallbladder: A dangerously misdiagnosed malformation

Isolated agenesis of the gallbladder is a rare anomaly, often asymptomatic. However, one patient out of four presented with right upper abdominal pain, nausea, and fatty food intolerance. The condition is frequently mistaken with an excluded or sclero-atrophic gallbladder, regardless of the imaging modality used. Consequently, AG often leads to unnecessary and potentially dangerous laparoscopic surgery as described in a few case reports over the last 10 years. The aim of this study is to clarify the diagnostic and therapeutic approach of this unusual pathology. Two cases seen in our institutions were retrospectively reviewed, together with a review of the American and European literature. During laparoscopy, the absence of normal anatomical structures and the impossibility of pulling on the gallbladder to expose and dissect the triangle of Callot increases the risk of iatrogenic injury to biliary or portal structures. Depending on the experiment of the surgeon in laparoscopic procedure, this has to be taken into account to decide a conversion to laparotomy. A high index of suspicion is necessary when interpreting the radiological images. In case of doubt, a MRI-cholangiography is mandatory. Because of possible inherited transmission, relatives with a history of biliary symptoms should be investigated.

Acute cholecystitis

Only 20-30% of patients with gallstones have symptoms and the probability of a patient with silent gallstones developing biliary-related pain is 1-2%, while the risk of developing a serious complication (e.g. empyema, perforation, peritonitis etc.) is less than 0.1% per year. Imaging techniques are important in establishing the diagnosis and evaluating the patient. Laparoscopic cholecystectomy (LC) is the golden standard for the management of symptomatic gallstones and there are two surgical treatment options: early cholecystectomy (same hospital admission) and interval (delayed) cholecystectomy (6-8 weeks after resolution of acute attack). Early LC has medical and socioeconomic advantages over interval LC. LC can be undertaken for the majority of patients with AC and in some high risk groups the postoperative mortality can even be reduced. LC in AC is associated with longer operating time, a higher rate of conversion and bile damage. Early diagnosis and early operation can prevent the development of complications associated with AC.

[Inflammatory diseases of the gall bladder and biliary system. I. Imaging--cholelithasis--inflammation of the gall bladder]

Cholelithiasis is the most common affliction of the gallbladder and biliary tract. Including its complications, gallstone disease represents the basis for cholecystitis and cholangitis in the majority of cases. Inflammatory diseases of the biliary system are divided into acute and chronic forms originating from the gallbladder as well as from the biliary tract. Although acute calculous cholecystitis is the most common form, gangrenous, and emphysematous inflammation of the gallbladder as well as gallbladder empyema are included in this group of diseases. In the chronic forms, calculous and acalculous inflammation is also differentiated. Recent developments in cross-sectional imaging in sonography, computed tomography, and magnetic resonance imaging offer numerous tools for depicting the biliary system with high diagnostic accuracy. Invasive imaging modalities of the biliary system are mainly used for therapeutic aspects.

MR Imaging of the Gallbladder and Biliary System

MR imaging is an established technique for the diagnosis of a spectrum of biliary and gallbladder pathologies and continues to improve with the advent of technologic advances, including new contrast agents and new sequences that are capable of improving upon the contrast resolution and signal-to-noise that are afforded by conventional MR imaging. These improvements already have shown promise for the increasing role of MRC as the initial modality in assessing living liver donors and evaluating post-operative hepato-biliary complications. Improved spatial resolution and the added functional or physiologic information afforded by MR imaging promise ever expanding clinical applicability and usefulness.

Magnetic Resonance Imaging of Maternal Diseases Causing Acute Abdominal Pain During Pregnancy

Evaluation of acute abdominal pain in a pregnant patient is a clinical challenge. In these patients, magnetic resonance imaging (MRI) can allow a systematic cross-sectional evaluation of the entire abdomen and can provide clinically useful information in a short enough time for emergent diagnosis. This pictorial essay demonstrates MRI findings of various maternal diseases that can present as acute abdominal pain in pregnant patients. Familiarity with these findings is important for the radiologist to make an accurate and prompt diagnosis.

MR imaging in abdominal emergencies

The use of MR imaging in the emergency setting is evolving. Clear indications include situations in need of contrast media when iodinated contrast cannot be administered or to facilitate assessments in pregnant patients and children when exposure to ionizing radiation is considered unacceptable. The availability of rapid, motion-immune sequences now makes MR imaging a feasible study in less cooperative patients extending the range of patients for whom a diagnostic study can be achieved. Capitalizing on the unique benefits of MR imaging there is optimism that MR imaging can eliminate test redundancy and impact patient care in a cost-effective manner. Further investigations are needed to identify the diagnostic algorithms for which this favorable use holds true.